Metallic stair



. J. LEHMAN METALLIC STAIR se t- 27., 1927;

' Filed March s, 1926 Patented Sept. 27, 1927.

carr es STATES OFF-ICE. I

JosErH LEI-IYMAN, or CLEVELAND, onto, .ississos'rera (Jessaminemew STEEL MANUFACTURING COMPANY; or CLEVELAND, onto, A-oon'roaa'rron or Application filed Marclifi, i 9 26. i SeriaPNo; 93,297.

My invention" relates to improvements in metallic stairs, and more particularly to stairways adapted alternatively for transportation inknockdown condition andready and cheap erection upon the premises, or for shop erection, as occasion demands.

The object of my invention is to provide a stairway comprising metallic tread and riser units of the simplest form which are suitably bent, unpunched or undrilled, and are associated with means for assembling the stairway without the use of rivets, whereby maximum economy in construction and erection is insured. l

The mostcommon mode of erecting metallic stairways involves the punching or drilling of the various members so that they may be riveted or bolted together individual ly to form a flight of the desired dimensions. Obviously this requires the accurate punching or drilling of the stringers, risers, and treads, and the more or less complex bending and shaping of the latter members in order to afford abutting or overlapping angles for their rivet-ed connections.

Accordingly, I have devised means for avoiding any riveted connections by providing suitably positioned transverse rods in paired alined relation for supporting the treads and assembling them rigidly in position between the stringers. The stringers are transversely united by the rods and secured by terminal nuts engagingthe threaded ends of said rods. Preferably the tread and riser members are integrally formed to interlock and afford a spring or compression member acting upon a supporting rod.

The details of my improved construction may be more readily explained by making reference to the accompanying drawings, wherein:

Figure 1 is a longitudinal section of a por tion of a flight of metallic stairs embodying my instant improvements.

Fig. 2 is a transverse section thereof, partially broken away, on line 2-2, Fig. 1.

Fig. 3 is an enlarged fragmentary section illustrating the spring orcompression connection between the tread and riser mem bers, and

Fig. 4 is a perspective view of the preferred tread and riser unit preferably employed in erecting the stairs.

Throughout the several figures of the drawings I have employed thesame character of reference to indicate similar parts.

- The stringers a, (not any desired length, comprise inetallic memb'ers flanged at top and bottom as a, a; said stringers being the only punched members-of the stairway and haVe' paired-alined openings-to receive the assemblin and supporting rods "corresponding with each tread. One of the tread members is shown in Fig. 4 and comprises a comb-inedtre'adb and riser b. The forward er ge 6 of the tread is bent at a slightly acute angle with its horizontal face, as best shownin Fig. 3, while the upper'portion of the riser'is bent' into "channel form 6 for the purpose of affording an interlocking connection between adjacent treads and risers supported by the forward transverse rod 0. The rear transverse rod cl is in av slightly lower plane at the angle of the tread and riser, and serves to support the latterdirectly upon the flanges a of the opposing stringers, as best shown in Fig. 2. The several members are united by the terminal nuts 0 d and c d which bring the stringers tightly into engagement with the ends of the treads and risers and afford a rigid and substantial stairway of extremely cheap construction.

The assembled stairway may then be erected as a flight in its intended location and the respective treads are filled with suitable composition 6 on a level with, the edges or channel portion 6 the lowermost step in fragmentary form, Fig. 1, having the tread portion unfilled and the next one above showing the tread portion. partially filled, for the sake of illustration, thereby a permanent flight of stairs, possessing maximum strength and the capacity for inserting renewable tread surfaces are provided for.

Referring particularly to Fig. 3, it will be observed that the edge or lip 12 serves resiliently to cramp the rod 0 within the inverted channel 6 meanwhile positioning the tread 'face in interlocking relation with the angular extension of the next lower riser. This type of combined tread and riser is peculiarly adapted for use in connection with knockdown flights of stairs, since the assemblage thereof requires no tools and extreme accuracy of construction is not demanded.

It Will be seen that the transverse rods used in completing the assemblage of the members between the lateral stringers serve to bring said stringers ti htly and evenly against the ends of the series of interlocked tread and riser members and form a substan tially unitary flight or stairway.

The exterior stringer desirably may be provided with capnuts 0, cl, Fig. 2, as screw-acting means for securing the rods exteriorly of the punched or drilled openings therefor, but these rods quite obviously may be otherwise assembled.

Extreme simplicity of construction and assemblage marks the-metallic stairs of my invention, largely contributed to by the unpunched tread and riser members employed, which interlock readily in place without the close of adjustment necessary for bolting or riveting them together or tothe supporting stringers.

Having now described the preferred em bodiment of my invention, I claim as new and desire to secure by Letters Patent, the following:

1. A combined tread and riser member for metallic stairs'comprising an integral tread e4as42 surface bent at right angles with the riser section, both of said sections being unpunched for riveted connection, but with an acute angular interlocking portion bent from the front edge of the tread, and a channeled re-entering portion bent from the upper edge of the riser for accommodating the interlocking portion of the next adjacent member rods extending through the punched openings in the stringers and engaging the angles of the respective tread and riser members in supporting relation upon the flanges of the stringers in assembled relation, substantially as set forth.

In testimony whereof I do now aifix my signature.

' JOSEPH LEHMAN. 

